A nano-diamond can exist in a powder form, and be manufactured by a high temperature and high pressure reaction and has high hardness. Generally, the nano-diamond has excellent wear resistance, scratch resistance, and the like, and a low frictional coefficient. Further, since the nano-diamond is chemically stable, corrosion resistance, acid resistance, and alkali resistance are excellent. In addition, due to a diamond structure, thermal conductivity is high and a thermal expansion coefficient is small. Therefore, the nano-diamond is a material which is suitable to be industrially applied.
Further, unlike other carbon materials, the nano-diamond has a high electrical resistance value, and thus may also be applied to a field requiring an insulating characteristic. Due to these characteristics, the nano-diamond has been continuously researched as a material for high efficiency of a heat exchanging medium.
A nano-diamond manufactured by a high temperature and high pressure explosion reaction has been manufactured in fine nano-particles having an average particle diameter of several tens of nanometers or less. As such, the nano-diamond has a wide specific surface area.
However, since the nano-diamond has the wide specific surface area, attractive force between particles may be strong. Therefore, the nano-diamond particles may form aggregates. The aggregates may cause some problems when the nano-diamond is used. For example, dispersion of the nano-diamond particles may be inferior without any treatment. Indeed, since the size of the nano-diamond particle required in the industry has gradually decreased, a demand for developing a dispersion stabilization technology for the nano-diamond has been grown.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.